Regeneration liquid and regeneration method of corrugated plate denitration catalyst

Abstract

The application provides a regeneration liquid and a regeneration method of corrugated plate denitration catalyst, and relates to the technical field of catalyst regeneration. The regeneration liquid comprises a three-stage cleaning liquid and an activity supplementing liquid; the three-stage cleaning liquid comprises an alkali cleaning liquid, an acid cleaning liquid and an oxidation liquid; and the activity supplementing liquid comprises vanadium salt, tungsten salt and nano TiO2 sol. The regeneration liquid can restore the denitration efficiency of the failed catalyst to more than 91% of that of a new catalyst. The high efficiency is derived from a strategy of "first deep cleaning, then double-effect recovery". The combination of the thorough cleaning and the synchronous regeneration of "chemical activity + physical structure" is the key to achieving the high-efficiency regeneration effect.

Description

Technical Field

[0001] This invention relates to the field of catalyst regeneration technology, and more specifically, to a regeneration solution and regeneration method for a corrugated plate denitrification catalyst. Background Technology

[0002] With the acceleration of industrialization, environmental protection has become a global focus. Nitrogen oxides (NOx) x NOx, as one of the major air pollutants, is crucial for improving air quality, protecting the ecological environment, and safeguarding human health. Among numerous denitrification technologies, selective catalytic reduction (SCR) technology is widely used due to its high efficiency and low energy consumption. The denitrification catalyst, as the core of SCR technology, directly determines the performance of NOx. x The removal efficiency. Common denitrification catalysts include corrugated plate, honeycomb, and flat plate types. Among them, corrugated plate catalysts are widely used in gas-fired power generation boilers, industrial boilers, and other fields due to their unique structural advantages, such as large specific surface area, light weight, high resistance to poisoning, and wide applicable temperature range.

[0003] During long-term operation of denitrification catalysts, the activity of the catalyst gradually decreases due to the presence of dust, heavy metals, and other harmful substances in the flue gas, resulting in deactivation. Catalyst deactivation mainly includes physical and chemical changes such as pore blockage, active site poisoning, and crystal structure sintering. With prolonged use, these deactivation factors accumulate, leading to a significant reduction in the catalyst's denitrification efficiency, failing to meet environmental emission standards. Currently, there are two main methods for treating deactivated catalysts: replacing the catalyst with a new one and catalyst regeneration. While replacing the catalyst with a new one can quickly restore denitrification efficiency, it is costly and generates a large amount of waste catalyst, potentially causing secondary pollution. In contrast, catalyst regeneration technology restores catalyst activity through physical or chemical methods, offering significant economic and environmental benefits, improving resource recycling rates, and reducing waste emissions.

[0004] Extensive research has been conducted in China on the regeneration of denitrification catalysts, yielding some results. However, existing technologies mainly focus on the regeneration of honeycomb and flat-plate catalysts, while regeneration technology for corrugated plate denitrification catalysts remains underdeveloped. The unique structure and material of corrugated plate catalysts require regeneration technologies with greater specificity and adaptability. Currently, some regeneration methods involve cleaning, alkaline cleaning, and acidic impregnation of the catalyst. However, these methods offer limited improvement in denitrification efficiency and do not significantly enhance the catalyst's mechanical strength or long-term stability.

[0005] Existing technologies for regenerating corrugated plate denitrification catalysts suffer from the following main drawbacks: First, the regeneration process is complex, involving multiple cleaning steps and activity recovery methods, resulting in long regeneration cycles and high costs, hindering large-scale industrial application. Second, the cleaning effect is unsatisfactory, failing to effectively remove accumulated dust, blockages, and deeply poisoned substances from the catalyst channels, affecting the activity and performance recovery of the regenerated catalyst. Third, activity recovery is insufficient; existing activity replenishment methods cannot fully restore the catalyst's initial activity, and the regenerated catalyst exhibits poor stability and is prone to reactivation. Finally, the improvement in catalyst mechanical strength is limited, failing to meet the strength requirements for long-term operation. Furthermore, existing technologies lack effective treatment solutions for pollutants such as wastewater and exhaust gas generated during the regeneration process, potentially causing secondary pollution. These problems limit the further development and widespread application of corrugated plate denitrification catalyst regeneration technology.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a regeneration solution and regeneration method for corrugated plate denitration catalysts. The regeneration solution can efficiently restore the catalyst performance to over 91%. The key lies in first thoroughly removing various contaminants that deactivate the catalyst through a three-stage cleaning process involving alkali, acid, and oxidation. Then, an active replenishing solution containing vanadium salts, tungsten salts, and nano-TiO2 is used to replenish chemical activity while simultaneously repairing the physical pore structure, ultimately achieving simultaneous regeneration of both chemical function and physical structure.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0009] In a first aspect, the present invention provides a regeneration liquid for a corrugated plate denitrification catalyst, comprising a three-stage cleaning liquid and an activity replenishing liquid; the three-stage cleaning liquid comprises an alkaline cleaning liquid, an acid cleaning liquid, and an oxidation liquid; the activity replenishing liquid comprises vanadium salt, tungsten salt, and nano-TiO2 sol.

[0010] In optional embodiments, the alkaline washing solution comprises 2wt%–15wt% ammonium bicarbonate, 1wt%–5wt% ethylenediaminetetraacetic acid (EDTA), and 4wt%–12wt% surfactant; or, the alkaline washing solution comprises 5wt%–10wt% ammonium bicarbonate, 2wt%–3wt% EDTA, and 5wt%–10wt% surfactant; and / or,

[0011] The pH of the alkaline washing solution is 8-11; or, the pH of the alkaline washing solution is 8-9; and / or,

[0012] The surfactant comprises at least one selected from dodecylbenzenesulfonic acid, coconut oil fatty acid monoethanolamide, polyethylene glycol monomethyl ether, polyoxyethylene ethyl ether, fatty alcohol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether; and / or,

[0013] The surfactant is a fatty alcohol polyoxyethylene ether; and / or,

[0014] The pickling solution comprises 0.5wt%~2wt% oxalic acid, 0.1wt%~0.5wt% ammonium bifluoride, 3wt%~30wt% ethanol, and 0.05wt%~0.2wt% pore-forming agent; or, the pickling solution comprises 0.6wt%~1.5wt% oxalic acid, 0.2wt%~0.4wt% ammonium bifluoride, 5wt%~20wt% ethanol, and 0.08wt%~0.16wt% pore-forming agent; and / or,

[0015] The pH of the pickling solution is 1-5; or, the pH of the pickling solution is 2-3; and / or,

[0016] The pore-forming agent includes at least one of urea, polyethylene oxide, dimethyl sulfoxide, silicon carbide nanowires, and carbon powder; and / or,

[0017] The oxidizing solution comprises 2wt%~5wt% hydrogen peroxide and 2wt%~8wt% citric acid; or, the oxidizing solution comprises 3wt%~4wt% hydrogen peroxide and 3wt%~6wt% citric acid; and / or,

[0018] The pH of the oxidizing solution is 1.5 to 5; or the pH of the oxidizing solution is 2 to 4.

[0019] In an optional embodiment, the active replenishing solution comprises 0.5wt%~3wt% vanadium salt, 1wt%~6wt% tungsten salt, 0.1wt%~1.5wt% acetamide, 0.1wt%~1.5wt% alkylphenol polyoxyethylene ether, 2wt%~20wt% nano-TiO2 sol, boric acid with a titanium molar ratio of 0%~8%, bismuth nitrate pentahydrate with a titanium molar ratio of 0%~8%, 0.1wt%~1wt% silane coupling agent, and 5wt%~30wt% vanadium salt. % ethanol; or, the active replenishing solution comprises 1wt%~2.5wt% vanadium salt, 2wt%~5wt% tungsten salt, 0.2wt%~1wt% acetamide, 0.2wt%~1wt% alkylphenol polyoxyethylene ether, 5wt%~10wt% nano-TiO2 sol, boric acid with a titanium molar ratio of 0%~5%, bismuth nitrate pentahydrate with a titanium molar ratio of 0%~5%, 0.2wt%~0.8wt% silane coupling agent, and 10~20wt% ethanol; and / or,

[0020] The pH of the active replenishing solution is 2-4; or, the pH of the active replenishing solution is 2.5-3.5; and / or,

[0021] The particle size of the nano-TiO2 sol is <20 nm; and / or,

[0022] The vanadium salt includes at least one selected from ammonium metavanadate, vanadium oxalate, ammonium vanadate, and ammonium pyrovanadate; and / or,

[0023] The tungsten salt includes at least one of ammonium metatungstate, ammonium tungstate, and ammonium paratungstate; and / or,

[0024] The silane coupling agent includes at least one of KH-550, KH-792 and A-1170.

[0025] Secondly, the present invention provides a method for regenerating a corrugated plate denitrification catalyst, based on the regeneration solution of the corrugated plate denitrification catalyst described in any of the foregoing embodiments; the method for regenerating the corrugated plate denitrification catalyst includes:

[0026] The catalyst to be treated is physically cleaned, and then subjected to a three-stage cleaning process using the alkaline washing solution, acid washing solution, and oxidizing solution in sequence.

[0027] The catalyst to be treated, after being washed with water until neutral, is then subjected to a first drying process.

[0028] The dried catalyst to be treated is impregnated and suction-treated using the aforementioned active replenishing solution;

[0029] The catalyst to be treated after impregnation and suction treatment is subjected to a second drying and calcination treatment to obtain a regenerated catalyst.

[0030] In an optional implementation, the physical cleaning includes at least one of high-pressure blowing and vacuuming; and / or,

[0031] The purging pressure for the physical cleaning is ±(0.1MPa~3MPa); or, the purging pressure for the physical cleaning is ±(0.5MPa~2MPa); and / or,

[0032] The physical cleaning blowing time is 0.1 hours to 2 hours; or, the physical cleaning blowing time is 0.5 hours to 1.5 hours.

[0033] In an optional embodiment, the treatment method for the alkaline washing solution in the three-stage cleaning process includes:

[0034] The catalyst to be treated is immersed in the alkaline washing solution for ultrasonic cleaning; wherein...

[0035] The ultrasonic cleaning temperature of the alkaline cleaning solution is 30℃~80℃; or, the ultrasonic cleaning temperature of the alkaline cleaning solution is 40℃~60℃; and / or,

[0036] The ultrasonic cleaning time of the alkaline cleaning solution is 0.5 hours to 4 hours; or, the ultrasonic cleaning time of the alkaline cleaning solution is 1 hour to 3 hours; and / or,

[0037] The ultrasonic cleaning frequency of the alkaline cleaning solution is 20kHz~50kHz; or, the ultrasonic cleaning frequency of the alkaline cleaning solution is 30kHz~40kHz; and / or,

[0038] The ultrasonic power of the alkaline cleaning solution for ultrasonic cleaning is 10W / L to 80W / L; or, the ultrasonic power of the alkaline cleaning solution for ultrasonic cleaning is 30W / L to 50W / L.

[0039] In an optional embodiment, the treatment method for the pickling solution in the three-stage cleaning process includes:

[0040] The catalyst to be treated, after being treated with the alkaline washing solution, is then washed with water for the first time.

[0041] The catalyst to be treated, after being washed with water, is then immersed in the acid washing solution for cleaning; wherein...

[0042] The soaking and cleaning time is 1 hour to 3 hours; or, the soaking and cleaning time is 1.5 hours to 2.5 hours; and / or,

[0043] The soaking and cleaning temperature is 10℃~30℃; or, the soaking and cleaning temperature is 15℃~25℃; and / or,

[0044] The first water wash lasts for 0.5 to 2 hours; or, the first water wash lasts for 0.5 to 1 hour.

[0045] In an optional embodiment, the treatment method for the oxidizing solution in the three-stage cleaning process includes:

[0046] The catalyst to be treated, after being treated with the pickling solution, is then washed a second time with water.

[0047] The catalyst to be treated, after being washed with water, is then bubbled and cleaned with the oxidizing solution; wherein...

[0048] The bubbling cleaning time is 1 hour to 3 hours; or, the bubbling cleaning time is 2 hours to 3 hours; and / or,

[0049] The bubbling cleaning temperature is 40℃~90℃; or, the bubbling cleaning temperature is 50℃~80℃; and / or,

[0050] The second water wash lasts for 0.5 to 2 hours; or, the second water wash lasts for 0.5 to 1 hour.

[0051] In an optional embodiment, the temperature of the first drying treatment is 80℃~150℃; or, the temperature of the first drying treatment is 90℃~130℃; and / or,

[0052] The first drying process takes 0.5 to 6 hours; or, the first drying process takes 1 to 4 hours; and / or,

[0053] The immersion time for the immersion suction treatment is 0.4 hours to 4 hours; or, the immersion time for the immersion suction treatment is 0.5 hours to 2 hours; and / or,

[0054] The suction pressure of the impregnation and suction treatment is -40 kPa to -100 kPa; or, the suction pressure of the impregnation and suction treatment is -50 kPa to -80 kPa; and / or,

[0055] The number of suction cycles for the immersion suction treatment is 0 to 6; or, the number of suction cycles for the immersion suction treatment is 1 to 4; and / or,

[0056] The second drying process includes a first stage and a second stage performed sequentially; wherein...

[0057] The drying temperature in the first stage is 30℃~60℃; or, the drying temperature in the first stage is 40℃~50℃; and / or,

[0058] The drying time for the first stage is 0.5 hours to 4 hours; or, the drying temperature for the first stage is 1 hour to 3 hours; and / or,

[0059] The drying temperature in the second stage is 90℃~130℃; or, the drying temperature in the second stage is 95℃~120℃; and / or,

[0060] The drying time for the second stage is 1 hour to 12 hours; or, the drying temperature for the second stage is 2 hours to 8 hours; and / or,

[0061] The roasting temperature of the roasting treatment is 360℃~420℃; or, the roasting temperature of the roasting treatment is 370℃~400℃; and / or,

[0062] The roasting time for the roasting treatment is 2 hours to 8 hours; or, the roasting time for the roasting treatment is 3 hours to 6 hours.

[0063] In an optional embodiment, before the step of impregnating and suction-treating the dried catalyst with the active replenishing solution, the method further includes: immersing the catalyst in a strength-enhancing solution for heat treatment; wherein...

[0064] The strength-enhancing liquid is a suspension prepared by mixing a reinforcing agent with a starch adhesive aqueous solution; and the reinforcing agent includes at least one of anatase, kaolin, γ-alumina powder, and silicon powder; and / or

[0065] The strength-enhancing liquid comprises the following components by mass fraction: anatase 45%~70%, kaolin 10%~30%, γ-alumina powder 5%~25%, silicon powder 2%~10%, and starch adhesive aqueous solution 3%~12%; or, the strength-enhancing liquid comprises the following components by mass fraction: anatase 50%~65%, kaolin 15%~25%, γ-alumina powder 10%~20%, silicon powder 3%~8%, and starch adhesive aqueous solution 5%~10%; and / or,

[0066] The heat treatment is as follows: heating from 1℃ to 5℃ to 150℃ to 220℃ and holding for 2 to 5 hours, then heating from 3℃ to 10℃ to 500℃ to 600℃ and holding for 1 to 5 hours; or heating from 2℃ to 3℃ to 180℃ to 210℃ and holding for 3 to 4 hours, then heating from 5℃ to 7℃ to 520℃ to 580℃ and holding for 2 to 4 hours.

[0067] This application provides a regeneration solution and regeneration method for a corrugated plate denitrification catalyst. The regeneration solution can efficiently restore the performance of a failed corrugated plate denitrification catalyst, achieving a denitrification efficiency of over 91% of that of a fresh catalyst, significantly superior to the 88% recovery level of some existing regeneration technologies. This remarkable effect is primarily due to its comprehensive and profound cleaning capabilities. Since catalyst failure is caused by a combination of factors such as pore blockage and poisoning, the three-stage cleaning solution in this composition achieves targeted removal of different contaminants through the sequential use of three different chemical environments: alkali, acid, and oxidation. The alkali cleaning solution mainly removes sulfates and alkaline earth metal ions, the acid cleaning solution removes alkali metals and arsenic-containing compounds, and the oxidation solution removes carbon powder blockages and metals such as zinc and lead. This step-by-step, targeted cleaning method is more thorough than a single treatment process, creating a clean physical basis for subsequent catalyst activity restoration.

[0068] After thorough cleaning, its unique active replenishment solution simultaneously achieves the dual goals of physical structure repair and chemical activity regeneration. By impregnating vanadium and tungsten salts, this liquid directly replenishes the core catalytically active materials that have been lost or degraded. More importantly, it also contains TiO2 sol with a particle size of less than 20 nanometers to repair the microporous structure of the catalyst coating and increase its specific surface area. This design ensures that the newly replenished active components not only load successfully but also have their physical structure repaired, thereby guaranteeing smooth contact between the flue gas and these active sites. It is this synergistic effect of combining chemical activity regeneration with physical structure repair that ultimately leads to a high degree of catalyst performance recovery. Attached Figure Description

[0069] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0070] Figure 1 This is a schematic diagram of the process for regenerating the corrugated plate denitrification catalyst provided in the embodiments of this application. Detailed Implementation

[0071] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0072] This application provides a regeneration solution for a corrugated plate denitrification catalyst, comprising a three-stage cleaning solution and an activation replenishment solution; the three-stage cleaning solution comprises an alkaline cleaning solution, an acid cleaning solution, and an oxidation solution; the activation replenishment solution comprises vanadium salt, tungsten salt, and nano-TiO2 sol.

[0073] The aforementioned "regeneration liquid of corrugated plate denitration catalyst" is not a single liquid, but a composition consisting of two core components:

[0074] (1) Three-stage cleaning solution: This is the first part of the regeneration process, which itself contains three different liquids: alkaline cleaning solution, acid cleaning solution and oxidizing solution. These three liquids need to be used in sequence to form a complete, step-by-step cleaning process.

[0075] (2) Active replenishment solution: This is the second part of the regeneration process and is a liquid used after the catalyst has been thoroughly cleaned. Its core components are limited to vanadium salt, tungsten salt and nano TiO2 sol.

[0076] The functional limitation of the tertiary cleaning solution lies in its "tertiary" characteristics, namely, using three different chemical environments—alkaline, acidic, and oxidizing—to remove different contaminants that cause catalyst deactivation in stages and in a targeted manner. During long-term use, catalysts accumulate various substances such as sulfates, alkali metals, heavy metals, and carbon soot particles. These substances have different chemical properties and are difficult to remove effectively with a single cleaning agent.

[0077] The alkaline washing solution is one component used to provide an alkaline environment. Its principle is to utilize the alkaline solution to neutralize acidic pollutants (such as sulfate deposits formed from sulfur oxides in flue gas), converting them into water-soluble substances, thereby removing them through cleaning.

[0078] Pickling solutions provide an acidic environment. The principle is to use acid to react with certain metallic contaminants that are neutral or alkaline in water (such as alkali metal compounds in flue gas ash) to form soluble salts that can be rinsed away.

[0079] The oxidizing liquid provides an oxidizing environment. Its principle is to use strong oxidizing properties to oxidize and decompose inert and insoluble carbon soot particles that are blocked in the micropores of the catalyst into gases such as carbon dioxide or easily soluble substances. At the same time, it can also oxidize some low-valence metal pollutants into more soluble high-valence ions.

[0080] The advantage of this step-by-step cleaning method lies in its comprehensiveness and thoroughness. Compared to using a single cleaning agent, this method can target specific problems, ensuring that different types of stubborn contaminants are effectively removed. This lays a very clean foundation for subsequent reactivation steps and avoids interference from residual substances on the regeneration effect.

[0081] The function of the active replenishment solution is to repair the physical structure of the catalyst and restore its chemical catalytic activity. This is based on the synergistic effect of "structural repair" and "activity reconstruction".

[0082] Vanadium (V) and tungsten (W) are the core active metal elements in vanadium-tungsten-titanium denitration catalysts. Vanadium and tungsten salts serve as supports for these metal elements in soluble ionic form. The principle is that by impregnating these salt solutions onto a cleaned catalyst support, followed by subsequent heat treatment, these salts decompose and transform into catalytically active metal oxides (mainly V₂O₅ and WO₃), thereby reconstructing the active sites of the catalyst.

[0083] For example, the commonly used vanadium salt "ammonium metavanadate" (NH4VO3) decomposes upon heating, and its simplified chemical reaction formula is as follows:

[0084] 2NH4VO3→V2O5+2NH3↑+H2O↑.

[0085] The V2O5 generated is the core of the catalytic reaction.

[0086] The aforementioned "sol" refers to a colloid formed by the stable dispersion of titanium dioxide (TiO2) nanoparticles in a liquid. TiO2 serves as the support framework for the catalyst. The principle is that, because these TiO2 particles are nanoscale (less than 20 nanometers in diameter), they are extremely small and can penetrate into the microscopic channels of the catalyst damaged by high temperatures or chemical corrosion. After subsequent drying and heat treatment, these particles fill and repair these microstructures, reconstructing a support with a high specific surface area. This high specific surface area is crucial for supporting and dispersing vanadium and tungsten active species, as well as ensuring sufficient contact between flue gas molecules and active sites.

[0087] The advantage of the active replenishment solution lies in its dual repair function. It doesn't simply recoat an active material onto an old, damaged carrier; instead, it first repairs the physical framework and then rebuilds the chemical function. This "treating both the symptoms and the root cause" approach ensures that the newly generated active sites have a good physical structure as support, thereby enabling a more complete and stable recovery of the catalyst's overall performance, ultimately achieving a high regeneration efficiency of over 91%.

[0088] In optional embodiments, the alkaline washing solution comprises 2wt% to 15wt% ammonium bicarbonate (e.g., 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, etc.), 1wt% to 5wt% ethylenediaminetetraacetic acid (e.g., 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, etc.), and 4wt% to 12wt% surfactant (e.g., 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, etc.); or, the alkaline washing solution comprises 5wt% to 10wt% ammonium bicarbonate, 2wt% to 3wt% ethylenediaminetetraacetic acid, and 5wt% to 10wt% surfactant; and / or,

[0089] The pH of the alkaline washing solution is 8-11 (e.g., it can be 8, 9, 10, 11, etc.); or, the pH of the alkaline washing solution is 8-9; and / or,

[0090] The surfactant comprises at least one selected from dodecylbenzenesulfonic acid, coconut oil fatty acid monoethanolamide, polyethylene glycol monomethyl ether, polyoxyethylene ethyl ether, fatty alcohol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether; and / or,

[0091] The surfactant is a fatty alcohol polyoxyethylene ether; and / or,

[0092] The pickling solution comprises 0.5wt%~2wt% oxalic acid (e.g., 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2, 1.5, 1.8, 2, etc.), 0.1wt%~0.5wt% ammonium bifluoride (e.g., 0.1, 0.2, 0.3, 0.4, 0.5, etc.), 3wt%~30wt% ethanol (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, etc.), and 0.05wt%~0.2wt% pore-forming agent (e.g., 0.05wt%); or, the pickling solution comprises 0.6wt%~1.5wt% oxalic acid, 0.2wt%~0.4wt% ammonium bifluoride, 5wt%~20wt% ethanol, and 0.08wt%~0.16wt% pore-forming agent; and / or,

[0093] The pH of the pickling solution is 1-5 (e.g., it can be 1, 2, 3, 4, 5, etc.); or, the pH of the pickling solution is 2-3; and / or,

[0094] The pore-forming agent includes at least one of urea, polyethylene oxide, dimethyl sulfoxide, silicon carbide nanowires, and carbon powder; and / or,

[0095] The oxidizing solution comprises 2 wt% to 5 wt% hydrogen peroxide (e.g., 2 wt%, 3 wt%, 4 wt%, 5 wt%, etc.) and 2 wt% to 8 wt% citric acid (e.g., 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, etc.); or, the oxidizing solution comprises 3 wt% to 4 wt% hydrogen peroxide and 3 wt% to 6 wt% citric acid; and / or,

[0096] The pH of the oxidizing solution is 1.5 to 5 (for example, it can be 1.5, 2, 3, 4, 5, etc.); or the pH of the oxidizing solution is 2 to 4.

[0097] In an optional embodiment, the active replenishing solution comprises 0.5wt%~3wt% vanadium salt (e.g., 0.5wt%, 0.6wt%, 0.8wt%, 1wt%, 2wt%, 3wt%, etc.), 1wt%~6wt% tungsten salt (e.g., 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, etc.), and 0.1wt%~1.5wt% acetamide (e.g., 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.2wt%, 1.3wt%). 0.1wt%~1.5wt% alkylphenol polyoxyethylene ether (e.g., 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.2wt%, 1.3wt%, 1.5wt%, etc.), 2wt%~20wt% nano-TiO2 sol (e.g., 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 13wt%, 15wt%, 20wt%, etc.), titanium molar ratio The composition includes 0%–8% boric acid (e.g., 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, etc.), 0%–8% bismuth nitrate pentahydrate (e.g., 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, etc.), 0.1 wt%–1 wt% silane coupling agent (e.g., 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, etc.), and 5 wt%–30 wt% ethanol (e.g., 5 wt%, 6 wt%, 8 wt%, 10 wt%). , 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%, 25wt%, 30wt%, etc.); or, the active replenishing solution includes 1wt%~2.5wt% vanadium salt, 2wt%~5wt% tungsten salt, 0.2wt%~1wt% acetamide, 0.2wt%~1wt% alkylphenol polyoxyethylene ether, 5wt%~10wt% nano-TiO2 sol, boric acid with a titanium molar ratio of 0%~5%, bismuth nitrate pentahydrate with a titanium molar ratio of 0%~5%, 0.2wt%~0.8wt% silane coupling agent, and 10~20wt% ethanol; and / or,

[0098] The pH of the active supplement solution is 2-4 (e.g., it can be 2, 2.2, 2.4, 2.5, 2.6, 2.7, 2.9, 3.0, 3.2, 3.4, 3.5, 4, etc.); or, the pH of the active supplement solution is 2.5-3.5; and / or,

[0099] The particle size of the nano-TiO2 sol is <20 nm; and / or,

[0100] The vanadium salt includes at least one selected from ammonium metavanadate, vanadium oxalate, ammonium vanadate, and ammonium pyrovanadate; and / or,

[0101] The tungsten salt includes at least one of ammonium metatungstate, ammonium tungstate, and ammonium paratungstate; and / or,

[0102] The silane coupling agent includes at least one of KH-550, KH-792 and A-1170.

[0103] refer to Figure 1 In this application embodiment, a method for regenerating a corrugated plate denitrification catalyst is provided, based on the regeneration solution of the corrugated plate denitrification catalyst described in any of the foregoing embodiments; the method for regenerating the corrugated plate denitrification catalyst includes:

[0104] Step S1: Physically clean the catalyst to be treated, and perform a three-stage cleaning process using the alkaline washing solution, acid washing solution and oxidizing solution in sequence.

[0105] The physical cleaning described above is a pretreatment step in the regeneration process. It involves a mechanical, non-chemical preliminary cleaning of the used (i.e., "to be treated") catalyst removed from the reactor. The process does not involve chemical reagents but rather uses physical methods to remove loose contaminants, such as floating ash, accumulated dust, and unburned particulate matter from the flue gas, that are attached to the catalyst surface and channels.

[0106] The result of this treatment is a catalyst with large particles and loose deposits removed from the surface. Its advantages are: 1) it avoids these loose impurities consuming chemicals in subsequent chemical cleaning, thus saving costs; 2) it prevents large particles from clogging the treatment equipment or affecting the uniform flow of the cleaning solution, improving the efficiency and uniformity of subsequent steps.

[0107] The tertiary cleaning process is the core chemical cleaning stage. Following physical cleaning, the catalyst is sequentially immersed in three liquids with different chemical properties to deeply remove chemical contaminants firmly bound to the catalyst. The process consists of three closely linked sub-steps:

[0108] (1) Alkaline washing: First, treat with alkaline liquid. The main goal is to remove acidic pollutants such as sulfates.

[0109] (2) Pickling: Then, acidic liquid is used for treatment, the main purpose of which is to remove alkali metals, arsenic compounds, etc.

[0110] (3) Oxidation washing: Finally, an oxidizing liquid is used for treatment. The main goal is to remove carbon soot particles and some metal that clog the micropores.

[0111] The result of this step is a chemically very clean catalyst support, with its internal micropores reopened and various chemical toxins adhering to its surface largely removed. Its advantages lie in the thoroughness and targeted nature of the cleaning. By addressing the root cause, it ensures that contaminants of different properties can be efficiently removed, providing an ideal carrier environment for the subsequent reloading of active components.

[0112] Step S2: After the catalyst has undergone three-stage cleaning, it is washed with water until neutral and then dried for the first time.

[0113] This step serves as a transition between chemical cleaning and active replenishment. It comprises two processes:

[0114] (1) Washing to neutral: After the three-stage cleaning (especially the final oxidation wash), the catalyst will be repeatedly rinsed with water free of impurities (preferably ultrapure water) until the pH of the wash water is neutral (about 7). Water washing is usually also performed between each chemical cleaning step.

[0115] (2) First drying: The washed catalyst is placed in an oven and heated to remove all the adsorbed moisture.

[0116] This step yields a chemically neutral, completely dry, and clean catalyst support. "Washing to neutral" ensures the complete removal of residual acids, alkalis, oxidants, and other chemicals, preventing them from interfering with subsequent replenishment solutions or causing secondary damage to the catalyst during high-temperature calcination. "Drying" ensures that the catalyst's pores are open and dry, allowing for maximum and uniform absorption of the subsequent replenishment solution.

[0117] Step S3: The dried catalyst to be treated is impregnated and suction-treated using the active replenishing solution.

[0118] This step is the core step in restoring catalyst activity. It involves completely immersing the clean, dry catalyst in the activation replenishment solution and forcing the liquid into all the tiny pores inside the catalyst by applying negative pressure (vacuum).

[0119] This step ensures that the catalyst support's inner and outer surfaces are uniformly and fully adsorbed with the active replenishing solution containing vanadium salt, tungsten salt, and nano-TiO2. Its main advantages are the depth and uniformity of impregnation. Compared to simple static soaking, "vacuuming" or "vacuuming" effectively removes the air from the pores, overcoming the surface tension of the liquid and allowing the replenishing solution to penetrate into the deepest micropores. This ensures that the final regenerated catalyst has a uniform activity distribution and high overall performance.

[0120] Step S4: The catalyst to be treated after impregnation and suction treatment is subjected to a second drying and calcination treatment to obtain a regenerated catalyst.

[0121] This is the final step in the regeneration process, a heat treatment process that transforms the liquid active precursor into a solid, stable active substance.

[0122] The first and second drying process involves heating at a relatively mild temperature. Its main purpose is to slowly evaporate the solvents (such as ethanol and water) in the active replenishment solution, so that the dissolved vanadium salt, tungsten salt, and nano-TiO2 particles are uniformly deposited in solid form on the pore surface of the catalyst support.

[0123] Calcination involves heating the catalyst at higher temperatures for an extended period. This process triggers chemical changes, which are crucial for imparting the catalyst with its final activity and stability.

[0124] The end result is a regenerated catalyst whose performance has been restored and which can be reused. The advantages of calcination are that it can chemically decompose the deposited vanadium salts, tungsten salts and other precursors, transforming them into stable oxide forms with catalytic activity (such as V2O5, WO3); it can firmly sinter the nano-TiO2 particles with the original support, completing the repair of the physical structure; and it can improve the mechanical strength and thermal stability of the regenerated catalyst.

[0125] In some embodiments, the physical cleaning includes at least one of high-pressure blowing and vacuuming.

[0126] In some embodiments, the purging pressure of the physical cleaning is ±(0.1MPa~3MPa) (for example, it can be ±0.1MPa, ±0.2MPa, ±0.3MPa, ±0.5MPa, ±1MPa, ±2MPa, ±3MPa, etc.); or, the purging pressure of the physical cleaning is ±(0.5MPa~2MPa).

[0127] In some embodiments, the physical cleaning purging time is 0.1 hours to 2 hours (e.g., 0.1 hours, 0.3 hours, 0.5 hours, 0.6 hours, 0.7 hours, 0.8 hours, 1 hour, 1.5 hours, 2 hours, etc.); or, the physical cleaning purging time is 0.5 hours to 1.5 hours.

[0128] In some embodiments, the treatment method for the alkaline washing solution in the three-stage cleaning process includes:

[0129] The catalyst to be treated is immersed in the alkaline washing solution for ultrasonic cleaning; wherein...

[0130] The ultrasonic cleaning temperature of the alkaline cleaning solution is 30℃~80℃ (e.g., 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, etc.); or, the ultrasonic cleaning temperature of the alkaline cleaning solution is 40℃~60℃; and / or,

[0131] The ultrasonic cleaning time of the alkaline cleaning solution is 0.5 hours to 4 hours (e.g., 0.5 hours, 0.7 hours, 0.9 hours, 1 hour, 2 hours, 3 hours, etc.); or, the ultrasonic cleaning time of the alkaline cleaning solution is 1 hour to 3 hours; and / or,

[0132] The ultrasonic cleaning frequency of the alkaline cleaning solution is 20kHz~50kHz (e.g., 20kHz, 30kHz, 40kHz, 50kHz, etc.); or, the ultrasonic cleaning frequency of the alkaline cleaning solution is 30kHz~40kHz; and / or,

[0133] The ultrasonic power of the alkaline cleaning solution for ultrasonic cleaning is 10W / L to 80W / L (for example, it can be 10W / L, 20W / L, 30W / L, 40W / L, 50W / L, 60W / L, 70W / L, 80W / L, etc.); or, the ultrasonic power of the alkaline cleaning solution for ultrasonic cleaning is 30W / L to 50W / L.

[0134] In some embodiments, the treatment method for the pickling solution in the three-stage cleaning process includes:

[0135] The catalyst to be treated, after being treated with the alkaline washing solution, is then washed with water for the first time.

[0136] The catalyst to be treated, after being washed with water, is then immersed in the acid washing solution for cleaning; wherein...

[0137] The soaking and cleaning time is 1 hour to 3 hours (e.g., 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, etc.); or, the soaking and cleaning time is 1.5 hours to 2.5 hours; and / or,

[0138] The soaking and cleaning temperature is 10℃~30℃ (e.g., 10℃, 15℃, 20℃, 25℃, 30℃, etc.); or, the soaking and cleaning temperature is 15℃~25℃; and / or,

[0139] The first water wash time is 0.5 hours to 2 hours (for example, it can be 0.5 hours, 0.6 hours, 0.7 hours, 0.8 hours, 0.9 hours, 1 hour, 1.5 hours, 2 hours, etc.); or, the first water wash time is 0.5 hours to 1 hour.

[0140] In some embodiments, the treatment method for the oxidizing solution in the three-stage cleaning process includes:

[0141] The catalyst to be treated, after being treated with the pickling solution, is then washed a second time with water.

[0142] The catalyst to be treated, after being washed with water, is then bubbled and cleaned with the oxidizing solution; wherein...

[0143] The bubbling cleaning time is 1 hour to 3 hours (e.g., 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, etc.); or, the bubbling cleaning time is 2 hours to 3 hours; and / or,

[0144] The bubbling cleaning temperature is 40℃~90℃ (e.g., 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, etc.); or, the bubbling cleaning temperature is 50℃~80℃; and / or,

[0145] The second wash time is 0.5 hours to 2 hours (for example, it can be 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, etc.); or, the second wash time is 0.5 hours to 1 hour.

[0146] In some embodiments, the temperature of the first drying treatment is 80°C to 150°C (e.g., 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, etc.); or, the temperature of the first drying treatment is 90°C to 130°C; and / or,

[0147] The first drying process takes 0.5 to 6 hours (e.g., 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6 hours, etc.); or, the first drying process takes 1 to 4 hours; and / or,

[0148] The immersion time for the impregnation and suction treatment is 0.4 hours to 4 hours (e.g., 0.4 hours, 0.5 hours, 0.8 hours, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 4 hours, etc.); or, the immersion time for the impregnation and suction treatment is 0.5 hours to 2 hours; and / or,

[0149] The suction pressure of the impregnation and suction treatment is -40 kPa to -100 kPa (for example, it can be -40 kPa, -50 kPa, -60 kPa, -70 kPa, -80 kPa, -90 kPa, -100 kPa, etc.); or, the suction pressure of the impregnation and suction treatment is -50 kPa to -80 kPa; and / or,

[0150] The number of suction cycles for the impregnation and suction treatment is 0 to 6 (e.g., 0, 1, 2, 3, 4, 5, 6, etc.); or, the number of suction cycles for the impregnation and suction treatment is 1 to 4; and / or,

[0151] The second drying process includes a first stage and a second stage performed sequentially; wherein...

[0152] The drying temperature in the first stage is 30℃~60℃ (e.g., 30℃, 40℃, 50℃, 60℃, etc.); or, the drying temperature in the first stage is 40℃~50℃; and / or,

[0153] The drying time for the first stage is 0.5 hours to 4 hours (e.g., 0.5 hours, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 4 hours, etc.); or, the drying temperature for the first stage is 1 hour to 3 hours; and / or,

[0154] The drying temperature in the second stage is 90℃~130℃ (e.g., 90℃, 95℃, 100℃, 110℃, 120℃, 130℃, etc.); or, the drying temperature in the first stage is 95℃~120℃; and / or,

[0155] The drying time for the second stage is 1 hour to 12 hours (e.g., 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 10 hours, 12 hours, etc.); or, the drying temperature for the second stage is 2 hours to 8 hours; and / or,

[0156] The calcination temperature of the calcination treatment is 360℃~420℃ (for example, it can be 360℃, 370℃, 380℃, 390℃, 400℃, 410℃, 420℃, etc.); or, the calcination temperature of the calcination treatment is 370℃~400℃; and / or,

[0157] The roasting time for the roasting treatment is 2 hours to 8 hours (for example, it can be 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, etc.); or, the roasting time for the roasting treatment is 3 hours to 6 hours.

[0158] In some embodiments, before the step of impregnating and suction-treating the dried catalyst with the active replenishing solution, the method further includes: immersing the catalyst in a strength-enhancing solution for heat treatment; wherein,

[0159] The strength-enhancing liquid is a suspension prepared by mixing a reinforcing agent with a starch adhesive aqueous solution; and the reinforcing agent includes at least one of anatase, kaolin, γ-alumina powder and silicon powder.

[0160] This step adds a pretreatment process specifically designed to enhance the physical strength of the catalyst before the activation replenishment (i.e., impregnation and suction treatment). This step is specifically applicable to catalysts that have become physically fragile and mechanically weak after years of use.

[0161] The main advantage lies in salvage and repair. For catalysts that may break during subsequent processing or reinstallation due to structural loosening or damage, this step can restore their mechanical strength by rebuilding their internal framework, enabling them to withstand subsequent regeneration processes and future operating environments. This expands the range of regenerable catalysts and improves the success rate and economic efficiency of the regeneration process.

[0162] This step involves two core processing steps: first, the catalyst is immersed in a special "strength-enhancing liquid," and then it undergoes a precisely controlled, multi-stage "heat treatment" process.

[0163] The strength-enhancing liquid comprises the following components by mass fraction: anatase 45%~70% (e.g., 45%, 50%, 55%, 60%, 65%, 70%, etc.), kaolin 10%~30% (e.g., 10%, 15%, 20%, 25%, 30%, etc.), γ-alumina powder 5%~25% (e.g., 5%, 10%, 15%, 20%, 25%, etc.), silicon powder 2%~10% (e.g., 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.), and starch adhesive aqueous solution 3%~12% (e.g., 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, etc.); or, the strength-enhancing liquid comprises the following components by mass fraction: anatase 50%~65%, kaolin 15%~25%, γ-alumina powder 10%~20%, silicon powder 3%~8%, and starch adhesive aqueous solution 5%~10%; and / or,

[0164] The heat treatment consists of heating from 1°C to 5°C (e.g., 1°C, 2°C, 3°C, 4°C, 5°C, etc.) to 150°C to 220°C and holding at that temperature (e.g., 150°C, 160°C, 180°C, 190°C, 200°C, 210°C, 220°C, etc.) for 2 to 5 hours (e.g., 2 hours, 3 hours, 4 hours, 5 hours, etc.), then heating from 3°C to 10°C to 500°C to 600°C (e.g., 500°C, 520°C, 540°C, 560°C, 580°C, 600°C, etc.) and holding at that temperature for 1 to 5 hours (e.g., 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, etc.); or heating from 2°C to 3°C to 180°C to 210°C and holding at that temperature for 3 to 4 hours, then heating from 5°C to 7°C to 520°C to 580°C and holding at that temperature for 2 to 4 hours.

[0165] The present invention will be further illustrated below with specific embodiments. However, it should be understood that these embodiments are merely for the purpose of more detailed illustration and should not be construed as limiting the present invention in any way.

[0166] Example 1

[0167] In this embodiment, the denitrification catalyst of the decommissioned corrugated plate is regenerated.

[0168] Experimental methods:

[0169] (1) Purge the denitrification catalyst of the decommissioned corrugated plate with high-pressure air of 0.5 MPa for 1.5 hours;

[0170] (2) Then place it in an alkaline washing solution at 40°C and vibrate it for 3 hours using an ultrasonic frequency of 30kHz and an ultrasonic power of 50W / L.

[0171] (3) After washing with water for 0.6 hours, soak in pickling solution at 15℃ for 2 hours.

[0172] (4) After washing with water for 0.5 hours, place it in a 50°C oxidizing solution for 3 hours of bubble cleaning, then wash with ultrapure water until neutral, and dry at 100°C for 3 hours.

[0173] (5) The dried catalyst was impregnated with an active replenishing solution for 2 hours, and then subjected to three suction cycles at -70 kPa. After drying in stages, the catalyst was dried at 40°C for 3 hours and then at 100°C for 6 hours. After calcination at 370°C for 6 hours, the regenerated catalyst was obtained.

[0174] The alkaline washing solution consists of 6 wt% ammonium bicarbonate, 2 wt% ethylenediaminetetraacetic acid, and 8 wt% polyethylene glycol monomethyl ether, with a pH of 8.27.

[0175] The pickling solution consisted of 0.8 wt% oxalic acid, 0.2 wt% ammonium bifluoride, 6 wt% ethanol, and 0.08 wt% silicon carbide nanowires, with a pH of 2.89.

[0176] The oxidizing solution consists of 3 wt% hydrogen peroxide and 3 wt% citric acid, with a pH of 3.54.

[0177] The active replenishment solution consists of 1.2 wt% ammonium pyrovanadate, 2 wt% ammonium tungstate, 0.3 wt% acetamide, 0.6 wt% alkylphenol polyoxyethylene ether, 7 wt% nano-TiO2 sol (particle size <20 nm), 1% boric acid (titanium molar ratio), 0.5% bismuth nitrate pentahydrate (titanium molar ratio), 0.2 wt% A-1170, and 10 wt% ethanol, with a pH of 3.05.

[0178] Example 2

[0179] In this embodiment, the denitrification catalyst of the decommissioned corrugated plate is regenerated.

[0180] Experimental methods:

[0181] (1) The denitrification catalyst of the decommissioned corrugated plate was vacuumed for 1 hour at -1.5MPa.

[0182] (2) Then place it in an alkaline washing solution at 50°C and vibrate it for 2 hours using an ultrasonic frequency of 40kHz and an ultrasonic power of 40W / L.

[0183] (3) After washing with water for 0.8 hours, soak in pickling solution at 25°C for 1.5 hours.

[0184] (4) After washing with water for 0.6 hours, place it in an oxidizing solution at 70°C and bubble it for 2 hours. Then wash it with ultrapure water until neutral and dry it at 120°C for 2 hours.

[0185] (5) The dried catalyst was impregnated with an active replenishing solution for 1.5 hours, and then dried in stages after being suctioned twice at -60 kPa, i.e., dried at 50°C for 2 hours and then dried at 110°C for 4 hours. After calcining at 400°C for 4 hours, the regenerated finished catalyst was obtained.

[0186] The alkaline washing solution consists of 8 wt% ammonium bicarbonate, 3 wt% ethylenediaminetetraacetic acid, and 6 wt% fatty alcohol polyoxyethylene ether (AEO-7), with a pH of 8.46.

[0187] The pickling solution consisted of 1 wt% oxalic acid, 0.3 wt% ammonium fluoride, 10 wt% ethanol and 0.12 wt% dimethyl sulfoxide, with a pH of 2.64.

[0188] The oxidizing solution consists of 4 wt% hydrogen peroxide and 4 wt% citric acid, with a pH of 3.02.

[0189] The active replenishment solution consists of 1.5 wt% ammonium metavanadate, 3 wt% ammonium metatungstate, 0.5 wt% acetamide, 0.8 wt% alkylphenol polyoxyethylene ether, 8 wt% nano-TiO2 sol (particle size <20 nm), 5% boric acid (titanium molar ratio), 1.5% bismuth nitrate pentahydrate (titanium molar ratio), 0.4 wt% KH-550, and 12 wt% ethanol, with a pH of 2.75.

[0190] Example 3

[0191] In this embodiment, the denitrification catalyst of the decommissioned corrugated plate is regenerated.

[0192] Experimental methods:

[0193] (1) Purge the denitrification catalyst of the decommissioned corrugated plate with high pressure air of 1 MPa for 1.2 hours.

[0194] (2) Place it in an alkaline washing solution at 60°C and vibrate it for 1.5 hours using an ultrasonic frequency of 40kHz and an ultrasonic power of 50W / L.

[0195] (3) After washing with water for 0.5 hours, soak in pickling solution at 20℃ for 1.5 hours.

[0196] (4) After washing with water for 0.8 hours, place it in an 80℃ oxidizing solution for 2 hours of bubble cleaning, then wash with ultrapure water until neutral, and dry at 90℃ for 4 hours.

[0197] (5) The dried catalyst was impregnated with an active replenishing solution for 1 hour, and then dried in stages after being suctioned twice at -50 kPa, i.e., dried at 40°C for 2 hours and then dried at 120°C for 5 hours. After calcining at 390°C for 5 hours, the regenerated finished catalyst was obtained.

[0198] The alkaline washing solution consisted of 10 wt% ammonium bicarbonate, 3 wt% ethylenediaminetetraacetic acid, and 7 wt% coconut oil fatty acid monoethanolamide, with a pH of 8.96.

[0199] The pickling solution consisted of 1.2 wt% oxalic acid, 0.4 wt% ammonium bifluoride, 15 wt% ethanol and 0.16 wt% urea, with a pH of 2.08.

[0200] The oxidizing solution consists of 3 wt% hydrogen peroxide and 6 wt% citric acid, with a pH of 2.93.

[0201] The active replenishment solution consists of 2.2 wt% ammonium vanadate, 4.5 wt% ammonium paratungstate, 0.8 wt% acetamide, 0.4 wt% alkylphenol polyoxyethylene ether, 6 wt% nano-TiO2 sol (particle size <20 nm), 2% boric acid (titanium molar ratio), 3% bismuth nitrate pentahydrate (titanium molar ratio), and 0.6 wt% KH-792.

[0202] 20wt% ethanol, pH 2.96.

[0203] Example 4

[0204] In this embodiment, the denitrification catalyst of the decommissioned corrugated plate is regenerated.

[0205] Experimental methods:

[0206] (1) Purge the denitrification catalyst of the decommissioned corrugated plate with high pressure air of 1.5 MPa for 1 hour.

[0207] (2) Place it in an alkaline washing solution at 50°C and vibrate it for 2.5 hours using an ultrasonic frequency of 30kHz and an ultrasonic power of 40W / L.

[0208] (3) After washing with water for 1 hour, soak in pickling solution at 25°C for 2 hours.

[0209] (4) After washing with water for 1 hour, place it in a 60°C oxidizing solution for 2.5 hours of bubble cleaning, then wash with ultrapure water until neutral, and dry at 110°C for 3 hours.

[0210] (5) The dried catalyst was impregnated with an active replenishing solution for 1 hour, and then subjected to three suction cycles at -60 kPa. After that, it was dried in stages, namely, dried at 50°C for 1 hour and then dried at 110°C for 5 hours. After calcining at 380°C for 6 hours, the regenerated finished catalyst was obtained.

[0211] The alkaline washing solution consists of 8 wt% ammonium bicarbonate, 2 wt% ethylenediaminetetraacetic acid, and 9 wt% fatty alcohol polyoxyethylene ether (AEO-3), with a pH of 8.74.

[0212] The pickling solution consisted of 1 wt% oxalic acid, 0.3 wt% ammonium bifluoride, 12 wt% ethanol and 0.1 wt% carbon powder, with a pH of 2.49.

[0213] The oxidizing solution consists of 3 wt% hydrogen peroxide and 3 wt% citric acid, with a pH of 2.76.

[0214] The active replenishment solution consists of 2wt% vanadium oxalate, 4.2wt% ammonium metatungstate, 0.6wt% acetamide, 0.8wt% alkylphenol polyoxyethylene ether, 10wt% nano-TiO2 sol (particle size <20nm), 4% boric acid (titanium molar ratio), 2% bismuth nitrate pentahydrate (titanium molar ratio), 0.4wt% KH-550, and 15wt% ethanol, with a pH of 2.13.

[0215] Performance testing experiment

[0216] 1. Testing method:

[0217] The regenerated catalyst prepared in the above examples was placed in a catalyst activity evaluation device for denitrification performance testing. The experimental conditions were as follows: H2O: 10%, O2: 3%, NO: 500 mg / Nm³. 3Ammonium-nitrogen ratio = 1:1, space velocity: 6900 h⁻¹ -1 The NO2 at the reactor outlet and inlet was detected using a flue gas analyzer. x The concentration is then used to calculate the denitrification efficiency of the regenerated catalyst.

[0218] 2. Test Results:

[0219] Table 1. Denitrification efficiency of catalysts after regeneration in different embodiments

[0220]

[0221] 3. Analysis:

[0222] In this test experiment, the performance of the regenerated catalysts obtained in the four examples was tested under fixed conditions such as water, oxygen, nitrogen oxide concentration, ammonium-nitrogen ratio, and space velocity, according to the performance testing experimental method. Table 1 shows the NO conversion rate of each regenerated catalyst.

[0223] The NO conversion rates of the regenerated catalysts obtained in Examples 1, 2, 3, and 4 were 91.43%, 91.76%, 91.57%, and 91.99%, respectively.

[0224] Analysis of the data shows that the regenerated catalysts prepared in all four examples exhibited high denitrification activity, with NO conversion rates all successfully exceeding 91%. This indicates that the range of regenerated liquid formulations and regeneration method process parameters disclosed in this invention are effective and can stably restore the performance of the degraded catalyst to the predetermined target.

[0225] In the four examples, although the activity differences were not significant, the regenerated catalyst of Example 4 exhibited the highest NO conversion rate, reaching 91.99%. This indicates that among the tested combinations, the specific process parameters and regenerated liquid formulation used in Example 4 were relatively optimal.

[0226] In summary, the test results strongly demonstrate the success of the regeneration solution and method provided by this invention. Under different parameter and component combinations, this technical solution can restore the activity of the failed corrugated plate denitrification catalyst to a level close to that of a new catalyst (above 91%). In the given examples, the regeneration effect of Example 4 is the best, with the highest catalyst denitrification efficiency reaching 91.99%.

[0227] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A regeneration solution for a corrugated plate denitrification catalyst, characterized in that, Includes a three-stage cleaning solution and an active replenishing solution; The three-stage cleaning solution includes alkaline cleaning solution, acid cleaning solution and oxidizing solution; The active replenishing solution comprises 0.5wt%~3wt% vanadium salt, 1wt%~6wt% tungsten salt, 0.1wt%~1.5wt% acetamide, 0.1wt%~1.5wt% alkylphenol polyoxyethylene ether, 2wt%~20wt% nano-TiO2 sol, 0%~8% boric acid relative to the molar ratio of titanium in the nano-TiO2 sol, 0%~8% bismuth nitrate pentahydrate relative to the molar ratio of titanium in the nano-TiO2 sol, 0.1wt%~1wt% silane coupling agent, and 5wt%~30wt% ethanol; The alkaline washing solution comprises 2wt% to 15wt% ammonium bicarbonate, 1wt% to 5wt% ethylenediaminetetraacetic acid, and 4wt% to 12wt% surfactant; The pickling solution comprises 0.5wt%~2wt% oxalic acid, 0.1wt%~0.5wt% ammonium bifluoride, 3wt%~30wt% ethanol and 0.05wt%~0.2wt% pore-forming agent; The oxidizing solution comprises 2wt%~5wt% hydrogen peroxide and 2wt%~8wt% citric acid.

2. The regeneration liquid of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The alkaline washing solution comprises 5wt% to 10wt% ammonium bicarbonate, 2wt% to 3wt% ethylenediaminetetraacetic acid, and 5wt% to 10wt% surfactant.

3. The regeneration liquid of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The pH of the alkaline washing solution is 8-11.

4. The regeneration solution of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The pH of the alkaline washing solution is 8-9.

5. The regeneration solution of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The surfactant includes at least one of dodecylbenzenesulfonic acid, coconut oil fatty acid monoethanolamide, polyethylene glycol monomethyl ether, polyoxyethylene ethyl ether, and fatty alcohol polyoxyethylene ether.

6. The regeneration solution of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The surfactant is a fatty alcohol polyoxyethylene ether.

7. The regeneration solution of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The pickling solution comprises 0.6wt%~1.5wt% oxalic acid, 0.2wt%~0.4wt% ammonium bifluoride, 5wt%~20wt% ethanol and 0.08wt%~0.16wt% pore-forming agent.

8. The regeneration solution of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The pH of the pickling solution is 1-5.

9. The regeneration solution of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The pH of the pickling solution is 2-3.

10. The regeneration solution of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The pore-forming agent includes at least one of urea, polyethylene oxide, dimethyl sulfoxide, silicon carbide nanowires, and carbon powder.

11. The regeneration liquid of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The oxidizing solution comprises 3wt%~4wt% hydrogen peroxide and 3wt%~6wt% citric acid.

12. The regeneration liquid of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The pH of the oxidation solution is 1.5~5.

13. The regeneration liquid of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The pH of the oxidizing solution is 2-4.

14. The regeneration liquid of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The active replenishing solution comprises 1wt%~2.5wt% vanadium salt, 2wt%~5wt% tungsten salt, 0.2wt%~1wt% acetamide, 0.2wt%~1wt% alkylphenol polyoxyethylene ether, 5wt%~10wt% nano-TiO2 sol, boric acid with a molar ratio of 0%~5% relative to titanium in the nano-TiO2 sol, bismuth nitrate pentahydrate with a molar ratio of 0%~5% relative to titanium in the nano-TiO2 sol, 0.2wt%~0.8wt% silane coupling agent, and 10~20wt% ethanol.

15. The regeneration liquid of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The pH of the active supplement solution is 2-4.

16. The regeneration liquid of the corrugated plate denitrification catalyst as described in claim 1, characterized in that, The pH of the active supplement solution is 2.5~3.

5.

17. The regeneration liquid of the corrugated plate denitrification catalyst as described in claim 14, characterized in that, The particle size of the nano-TiO2 sol is <20nm.

18. The regeneration liquid of the corrugated plate denitrification catalyst as described in claim 14, characterized in that, The vanadium salt includes at least one of ammonium metavanadate, vanadium oxalate, ammonium vanadate, and ammonium pyrovanadate.

19. The regeneration liquid of the corrugated plate denitrification catalyst as described in claim 14, characterized in that, The tungsten salt includes at least one of ammonium metatungstate, ammonium tungstate, and ammonium paratungstate.

20. The regeneration liquid of the corrugated plate denitrification catalyst as described in claim 14, characterized in that, The silane coupling agent includes at least one of KH-550, KH-792 and A-1170.

21. A method for regenerating a corrugated plate denitrification catalyst, characterized in that, The regeneration solution based on the corrugated plate denitration catalyst according to any one of claims 1-20; the regeneration method of the corrugated plate denitration catalyst includes: The catalyst to be treated is physically cleaned, and then subjected to a three-stage cleaning process using the alkaline washing solution, acid washing solution, and oxidizing solution in sequence. The catalyst to be treated, after being washed with water until neutral, is then subjected to a first drying process. The dried catalyst to be treated is impregnated and suction-treated using the aforementioned active replenishing solution; The catalyst to be treated after impregnation and suction treatment is subjected to a second drying and calcination treatment to obtain a regenerated catalyst.

22. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The physical cleaning includes at least one of high-pressure blowing and vacuuming.

23. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The purging pressure for the physical cleaning is ±(0.1MPa~3MPa).

24. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The purging pressure for the physical cleaning is ±(0.5MPa~2MPa).

25. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The physical cleaning purging time is 0.1 hours to 2 hours.

26. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The physical cleaning purging time is 0.5 hours to 1.5 hours.

27. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, In the three-stage cleaning process, the treatment method for the alkaline cleaning solution includes: The catalyst to be treated is immersed in the alkaline washing solution for ultrasonic cleaning; wherein... The ultrasonic cleaning temperature of the alkaline cleaning solution is 30℃~80℃.

28. The method for regenerating the corrugated plate denitrification catalyst as described in claim 27, characterized in that, The ultrasonic cleaning temperature of the alkaline cleaning solution is 40℃~60℃.

29. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The ultrasonic cleaning time of the alkaline cleaning solution is 0.5 hours to 4 hours.

30. The method for regenerating the corrugated plate denitrification catalyst as described in claim 29, characterized in that, The ultrasonic cleaning time of the alkaline cleaning solution is 1 to 3 hours.

31. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The ultrasonic frequency of the ultrasonic cleaning with the alkaline cleaning solution is 20KHz~50KHz.

32. The method for regenerating the corrugated plate denitrification catalyst as described in claim 31, characterized in that, The ultrasonic frequency of the ultrasonic cleaning with the alkaline cleaning solution is 30kHz~40kHz.

33. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The ultrasonic power of the alkaline cleaning solution for ultrasonic cleaning is 10W / L~80W / L.

34. The method for regenerating the corrugated plate denitrification catalyst as described in claim 33, characterized in that, The ultrasonic power of the alkaline cleaning solution for ultrasonic cleaning is 30W / L~50W / L.

35. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, In the three-stage cleaning process, the treatment method for the pickling solution includes: The catalyst to be treated, after being treated with the alkaline washing solution, is then washed with water for the first time. The catalyst to be treated, after being washed with water, is then immersed in the acid washing solution for cleaning; wherein... The soaking and cleaning time is 1 hour to 3 hours; or, the soaking and cleaning time is 1.5 hours to 2.5 hours; and / or, The soaking and cleaning temperature is 10℃~30℃; or, the soaking and cleaning temperature is 15℃~25℃; and / or, The first water wash lasts for 0.5 to 2 hours; or, the first water wash lasts for 0.5 to 1 hour.

36. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, In the three-stage cleaning process, the method for treating the oxidizing solution includes: The catalyst to be treated, after being treated with the pickling solution, is then washed a second time with water. The catalyst to be treated, after being washed with water, is then bubbled and cleaned with the oxidizing solution; wherein... The bubbling cleaning time is 1 hour to 3 hours; or, the bubbling cleaning time is 2 hours to 3 hours; and / or, The bubbling cleaning temperature is 40℃~90℃; or, the bubbling cleaning temperature is 50℃~80℃; and / or, The second water wash lasts for 0.5 to 2 hours; or, the second water wash lasts for 0.5 to 1 hour.

37. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The temperature of the first drying process is 80℃~150℃.

38. The method for regenerating the corrugated plate denitrification catalyst as described in claim 37, characterized in that, The temperature of the first drying process is 90℃~130℃.

39. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The first drying process takes 0.5 to 6 hours.

40. The method for regenerating the corrugated plate denitrification catalyst as described in claim 39, characterized in that, The first drying process takes 1 to 4 hours.

41. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The immersion time for the immersion suction treatment is 0.4 hours to 4 hours.

42. The method for regenerating the corrugated plate denitrification catalyst as described in claim 41, characterized in that, The immersion time for the immersion suction treatment is 0.5 hours to 2 hours.

43. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The suction pressure for the impregnation and suction treatment is -40 kPa to -100 kPa.

44. The method for regenerating the corrugated plate denitrification catalyst as described in claim 43, characterized in that, The suction pressure for the impregnation and suction treatment is -50 kPa to -80 kPa.

45. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The number of suction cycles for the immersion suction treatment is 1 to 6.

46. ​​The method for regenerating the corrugated plate denitrification catalyst as described in claim 45, characterized in that, The number of suction cycles for the immersion suction treatment is 1 to 4.

47. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, The second drying process includes a first stage and a second stage performed sequentially; wherein... The drying temperature in the first stage is 30℃~60℃; or, the drying temperature in the first stage is 40℃~50℃; and / or, The drying time for the first stage is 0.5 hours to 4 hours; or, the drying temperature for the first stage is 1 hour to 3 hours; and / or, The drying temperature in the second stage is 90℃~130℃; or, the drying temperature in the second stage is 95℃~120℃; and / or, The drying time for the second stage is 1 hour to 12 hours; or, the drying temperature for the second stage is 2 hours to 8 hours; and / or, The roasting temperature of the roasting treatment is 360℃~420℃; or, the roasting temperature of the roasting treatment is 370℃~400℃; and / or, The roasting time for the roasting treatment is 2 hours to 8 hours; or, the roasting time for the roasting treatment is 3 hours to 6 hours.

48. The method for regenerating the corrugated plate denitrification catalyst as described in claim 21, characterized in that, Before performing the impregnation and suction treatment on the dried catalyst using the active replenishing solution, the step further includes: immersing the catalyst in a strength-enhancing solution for heat treatment; wherein... The strength-enhancing liquid is a suspension prepared by mixing a reinforcing agent with a starch adhesive aqueous solution; and the reinforcing agent includes at least one of anatase, kaolin, γ-alumina powder, and silicon powder; and / or The strength-enhancing liquid comprises the following components by mass fraction: anatase 45%~70%, kaolin 10%~30%, γ-alumina powder 5%~25%, silicon powder 2%~10%, and starch adhesive aqueous solution 3%~12%; or, the strength-enhancing liquid comprises the following components by mass fraction: anatase 50%~65%, kaolin 15%~25%, γ-alumina powder 10%~20%, silicon powder 3%~8%, and starch adhesive aqueous solution 5%~10%; and / or, The heat treatment is as follows: heating from 1℃ to 5℃ to 150℃ to 220℃ and holding for 2 to 5 hours, then heating from 3℃ to 10℃ to 500℃ to 600℃ and holding for 1 to 5 hours; or heating from 2℃ to 3℃ to 180℃ to 210℃ and holding for 3 to 4 hours, then heating from 5℃ to 7℃ to 520℃ to 580℃ and holding for 2 to 4 hours.

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